Skeletal System

The skeletal system is responsible for several important functions such as providing support to the body, aiding in movement, storing minerals such as calcium and phosphorus, and protecting vital organs. However, metabolism is not a function of the skeletal system. Metabolism is the process of converting food into energy and nutrients required by the body, and this process occurs mainly in the liver, pancreas, and other organs of the digestive system.

Cartilage is a type of connective tissue. The skeletal system is made up of bones and cartilages, which are both specialised connective tissues. Cartilages have a slightly pliable matrix, unlike bones, which possess a hard matrix. Cartilage is found in many parts of the body, including the ears, nose, and joints, where it acts as a cushion between bones.

The matrix of cartilages is made up of chondrocytes and a gel-like extracellular matrix. This matrix is composed of water, collagen fibers, and proteoglycans, including chondroitin sulfate. The chondroitin sulfate gives cartilage its resistance to compression and its slightly pliable nature.

The adult human body has a total of 206 bones. However, the number of bones in a human body changes over time. At birth, the human body has about 270 bones, which eventually fuse together as we grow up, resulting in the adult number of 206 bones. The skeletal system serves several functions, including support, protection, and movement.

The axial skeleton is the portion of the human skeletal system that consists of bones along the body's central axis. It includes the skull, vertebral column, and rib cage. In total, there are 80 bones in the axial skeleton. These bones provide support and protection for the body's vital organs and also serve as attachment points for muscles that allow for movement.
The skull is composed of 22 bones that are fused together, except for the mandible (lower jawbone) which is movable. The vertebral column is made up of 33 individual vertebrae that are separated by intervertebral discs. The thoracic cage, which protects the organs of the chest, consists of the sternum and 12 pairs of ribs, bringing the total number of bones in the axial skeleton to 80.
It's important to note that while there are 80 bones in the axial skeleton, the total number of bones in the human body is 206. The remaining 126 bones are part of the appendicular skeleton, which includes the bones of the arms, legs, pelvis, and shoulder girdle.
In summary, the axial skeleton comprises 80 bones, including those in the skull, vertebral column, and thoracic cage, and provides support and protection for the body's organs while allowing for movement through muscle attachment points.

The axial skeleton and the appendicular skeleton are the two parts of the skeletal system in the human body. The axial skeleton includes the bones along the central axis of the body, such as the skull, sternum, vertebral column, and ribs. The clavicle, also known as the collarbone, is not part of the axial skeleton but rather a part of the appendicular skeleton. The appendicular skeleton consists of the bones of the arms, legs, pelvis, and shoulder girdle. Therefore, option A, the clavicle, is the bone that is not part of the axial skeleton.

The human skull is composed of 22 bones, which are divided into two categories: cranial bones and facial bones. The cranial bones make up the skull's top and back portions, while the facial bones make up the front part of the skull. There are 8 cranial bones and 14 facial bones. Therefore, option D, which is 14, is the number of facial bones that the skull possesses. The facial bones include the maxilla, zygomatic, nasal, lacrimal, palatine, inferior nasal conchae, vomer, and mandible. These bones are responsible for giving the face its shape, protecting the eyes, nose, and mouth, and supporting the teeth.

The hyoid bone is a unique bone located in the neck that does not articulate with any other bone. It is horseshoe-shaped, resembling a "U." The bone sits at the base of the oral cavity, suspended by muscles and ligaments. The hyoid bone is an essential component in the movement and function of the tongue, larynx, and pharynx.

Humans possess two occipital condyles. These condyles are oval shaped structures that are located on the inferior surface of the occipital bone. They articulate with the superior articular facets of the atlas vertebra. The occipital condyles are important for the stability and movement of the head on the vertebral column.

The vertebral column, also known as the spinal column or spine, is composed of 26 vertebrae in the human body. These vertebrae are divided into five regions based on their location: cervical, thoracic, lumbar, sacral, and coccygeal. The cervical region consists of seven vertebrae, the thoracic region consists of twelve vertebrae, and the lumbar region consists of five vertebrae. The sacral region consists of one fused bone, the sacrum, and the coccygeal region consists of one fused bone, the coccyx. The vertebral column serves as a protective casing for the spinal cord and also provides structural support for the body.

The vertebral column of humans consists of 26 vertebrae, and each vertebra has a central hollow portion called the neural canal. This canal is responsible for housing and protecting the spinal cord, which is a crucial component of the nervous system. The spinal cord carries signals between the brain and the rest of the body, enabling functions such as movement, sensation, and organ control.

The occipital condyles are two rounded processes located on the inferior surface of the occipital bone. The atlas, which is the first cervical vertebra of the vertebral column, articulates with the occipital condyles to support the weight of the skull and allow for its movement. This joint is known as the atlanto-occipital joint and is responsible for the nodding and shaking movements of the head. The atlas is unique among the vertebrae in that it has no body or spinous process, but instead consists of an anterior and posterior arch and two lateral masses.

The human vertebral column is composed of 26 vertebrae that are divided into five different regions. These regions are the cervical region (7 vertebrae), thoracic region (12 vertebrae), lumbar region (5 vertebrae), sacral region (1 fused vertebra), and coccygeal region (1-4 fused vertebrae). Each region has unique features that contribute to its function in supporting the body and protecting the spinal cord.

The vertebral column of humans is composed of 26 vertebrae which are divided into different regions. The lumbar region of the vertebral column consists of five vertebrae. These five lumbar vertebrae are located in the lower back area of the vertebral column, below the thoracic vertebrae and above the sacral vertebrae. The lumbar vertebrae are larger in size and stronger than the other vertebrae in the vertebral column, and are responsible for supporting the weight of the upper body. The spinal nerves that exit from the vertebral column in the lumbar region supply the lower limbs, pelvic organs, and some of the muscles of the lower back.

The vertebral column, also known as the spine, has several important functions such as providing support to the head, protecting the spinal cord, and serving as a point of attachment for ribs. However, it does not protect all vital organs in the body. The vital organs, such as the heart and lungs, are protected by other structures in the body such as the rib cage and sternum.

The sternum, also known as the breast bone, is a flat bone located in the midline of the thorax or chest. It is present ventrally in the body and serves as the point of attachment for the ribs. The thoracic region of the spine is located between the cervical region (neck) and the lumbar region (lower back). Therefore, option C is the correct answer.

The human body has a total of 12 pairs of ribs that are attached dorsally to the vertebral column and ventrally to the sternum with the help of hyaline cartilage. The first seven pairs of ribs are called true ribs, while the remaining five pairs are called false ribs or floating ribs. The true ribs are so named because they directly articulate with the sternum via their costal cartilages, while the false ribs either attach indirectly to the sternum or not at all. Therefore, the correct option is A) 7 pairs.

The human body has 12 pairs of ribs, which articulate with the vertebral column dorsally and with the sternum ventrally with the help of hyaline cartilage. Hyaline cartilage is a precursor of bone.

The rib cage is a skeletal structure composed of three main components, namely the vertebral column, the ribs, and the sternum. The vertebral column forms the posterior aspect of the rib cage and provides a bony framework for the attachment of the ribs. The ribs are a series of curved bones that attach to the thoracic vertebrae and curve around the chest to connect to the sternum in the front. The sternum is a flat bone located in the center of the chest that serves as the attachment point for the ribs. The spinal cord, on the other hand, is a part of the central nervous system that runs through the vertebral column but is not a component of the rib cage.

Each limb of the human body has 30 bones. These bones along with their respective girdles constitute the appendicular skeleton. The appendicular skeleton is one of the two major divisions of the skeletal system, with the axial skeleton being the other. The axial skeleton is composed of the bones of the skull, vertebral column, and rib cage, while the appendicular skeleton comprises the bones of the upper and lower limbs, as well as the pectoral and pelvic girdles.

The human hand is composed of several bones, including the humerus, ulna, radius, carpals or wrist bones (8 in number), metacarpals or palm bones (5 in number), and phalanges (14 in number). Therefore, humans possess five bones in the palm of each hand.

The scapula, also known as the shoulder blade, is a flat triangular bone located in the upper back. It is connected to the clavicle, or collarbone, and the humerus, or upper arm bone. One of the structures that can be found on the scapula is the acromion, which is a flat, expanded process present on the spine of the scapula. The spine of the scapula is a slightly elevated ridge which is present on the dorsal, flat and triangular body of the scapula. The tibia, on the other hand, is a long bone located in the lower leg, while the patella is a sesamoid bone located in the knee joint. The ischium is a bone located in the pelvis.

The coxal bone, also known as the hip bone, is formed by the fusion of three bones- the ilium, the ischium, and the pubis. The ilium is the largest of the three bones and forms the superior aspect of the hip bone. The ischium forms the posteroinferior aspect of the hip bone and is the bone that bears the weight of the body when sitting. The pubis is the anterior aspect of the hip bone and is joined to the pubis of the opposite hip bone by a fibrocartilaginous joint called the pubic symphysis. The acromion, on the other hand, is a part of the scapula, which is a bone of the shoulder girdle and is not a part of the coxal bone.